고분자 블렌드를 통한 유기 전계효과 트랜지스터(OFET)의 전기적 특성 향상 및 NO2 가스 센서로의 응용

Abstract

Improvement of electrical properties of organic field-effect transistor (OFET) through polymer blend and application to NO2 gas sensor Rae-Su Park Advisor : Ph.D./Prof. Jae-Wook Lee Department of Chemical Engineering Graduate School of Chosun University Poly(3-hexylthiophene) (P3HT) film-based organic field-effect transistor (OFET) gas sensors have attracted considerable attention for their applicability in detecting nitric oxide gas. However, the current devices are limited in their gas sensing capabilities. This limitation stems from the low charge transport properties in the pure P3HT polymer film. In this study, we demonstrate that composites of two types of P3HT polymers, namely Regio-regular (RR) P3HT and Regio-random (RRa) P3HT, can enhance the sensing performance of OFET gas sensors. Additionally, we conducted a systematic investigation into the influence of RRa-P3HT on the gas sensing properties of P3HT film-based OFET sensors by varying the concentration of RRa-P3HT in the composite films. The resulting films were utilized in OFET devices for the detection of NO2 gas at room temperature. In terms of the results, the composite films of RR and RRa P3HT with 10 wt% RRa-P3HT showed a maximum charge carrier mobility of approximately 7.4 × 10−2 cm2 V−1 S−1, which was approximately four times higher than that of RR-P3HT films. The fabricated OFET sensors based on RR-RRa P3HT composite films exhibited significantly improved NO2 gas sensing properties compared to the bare RR-P3HT sensor. The sensor based on the RR-RRa P3HT composite (90/10) films demonstrated the best sensing performance compared to the bare RR-P3HT sensor when exposed to 10 ppm NO2 gas. It exhibited a responsivity of 30976% compared to 5154% for the bare RR-P3HT sensor, and a response time of 1.50 minutes compared to 1.93 minutes for the bare RR-P3HT sensor. These results highlight the significant potential of incorporating RRa-P3HT to enhance the gas sensing properties of P3HT film-based OFET gas sensors.